Spark plug



J. C. SULE ET AL SPARK PLUG Filed July 12,

INVEM n.

ATT OWN! Patented Jan. 8 1924.

UNI ED STATES PATENT OFFICE.

SPARK PLUG.

Application filed July 12, 1922. Serial No. 574,872.

To all whom it may oncern:

Be it known that we, JOHN C. SULE and WILLIAM WYATT, citizens of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented new and useful Improvements in Spark Plugs, of which the following is a specification.

This invention relates to improvements in spark plugs and has for an object the provision or" means for heating the plug, so as to facilitate firing the fuel charge and thus render starting easier and otherwise increase the efficiency of the engine.

Another object of the invention is the provision of aplug of this type having novel means for arranging the heating element to hold the same rigid and for connecting the said element in an electric circuit.

with the above and other objects in view, the invention further includes the following novel features and details of construction, to be hereinafter more fully described, illus' trated in the accompanying drawings and pointed out/in the appended claim.

In the drawings the figure shown represents the invention in longitudinal section.

Referring in detail to the drawing, wherein like characters of reference denote corresponding parts, the reference character 10 indicates the casing or housing of the plug which is formed of metal and which is provided with a bore 11 having atone end an enlarged threaded recess 12, within which extends a porcelain or other insulated core 13. This core is held in place by means of a threaded nut or bushing 14, gaskets 15 being provided upon opposite sides of an annular extension or flange 17 formed on the core 13 so as to prevent leakage of compression.

The core 13 is provided with areduced extension 18 which projects into the bore 11 and the said core is further provided with a longitudinal bore through which passes a power electrode 19, the latter extending downwardly through the bore 11 and bein spaced from a ground electrode 2( carr 1e by the casing or housing 10. ThlS casing or housing is provided with a threaded exshoulder tension 21 which euga es the usual threaded spark plug opening 0 an internal combustion engine.

Located within the'bore 10 and having one end extending over the extension 18 of the core 13 is a resistance coil 22 having a central bore for the passage of the power electrode 19. Each end of the coil 20 is provided with a contact collar 23 and surrounding the extension 18 of the core 13 and located between one of the collars 23 and a 24 formed at the inner end of the said extension 18, is a coiled spring 25. The other collar 23 at the opposite end of the coil 22 bears against a stop 26 which extends through the wall of the bore 11, said stop being shown in the form of an annular flange.

Extending through the core 13 is a contact terminal 27, whose inner end engages the coiled spring 25 and Whose outer end projects beyond the outer end of the core for connection with a suitable source of electric current.

The invention is susceptible of various changes in its form, proportions and minor details of construction and the right is herein reserved to make such changes as properly fall within the scope of the appended claim.

Having described the invention what is claimed is A spark plug embodying a housing. power and ground housing and having a reduced extension projecting into one end of the housing and defining a shoulder at the inner end of said extension, a resistanc coil located within the housing and having one end surrounding the core extension, a coiled spring surrounding said extension between the coil and shoulder, a stop within the housing for'engagement with the opposite end of the coil and a terminal extending through the core and having one end engaging the spring.

tures.

JOHN CASIMIR SULE. WILLIAM WYATT.

electrodes, a core secured to the In testimony whereof we ailix our signa- 

